Synergistic herbicidal composition for the selective control of weeds in cereals

ABSTRACT

SYMERGISTIC COMBINATION OF 1-(BENZOTHIAZOL-2&#39;&#39;-YL)-1,3DIMETHYL-UREA AND 2-(CHLORO AND METHYL)-4-CHLORO-PHENOXY-(ACETIC AND A-PROPIONIC) ACID SALTS AND ESTERS, WHICH POSSESES SYNERGISTIC HERBICIDAL PROPERTIES ESPECIALLY FOR THE SELECTIVE CONTROL OF WEEDS IN CERAL CULTIVATION.

United States Oflice 3,682,614 Patented Aug. 8, 1972 US. Cl. 71-90 12 Claims ABSTRACT OF THE DISCLOSURE Synergistic combination of 1-(benzothiazol-2-yl)-1,3- dimethyl-urea and 2-(chloro and methyl)-4-chloro-phenoxy-(acetic and a-propionic) acid salts and esters, which possesses synergistic herbicidal properties especially for the selective control of weeds in cereal cultiv'ations.

This application is a continuation of Ser. No. 760,680 filed Sept. 18, 1968, now abandoned.

The present invention relates to and has for its objects the provision for new herbicidal compositions in the form of synergistic combinations of certain individually known compounds, which combinations possess outstanding herbicidal properties, optionally in the form of carrier composition mixtures of such synergistic combinations with solid and/or liquid dispersible carrier vehicles, and methods for using such synergistic combinations in a new way especially for combating weeds, e.g. in cereal cultivation, with other further objects becoming apparent from a study of the within specification and accompanying examples.

It is known that 1(benzothiazol-2yl)-l,3-dimethylurea (1a) can be used as a herbicide (see US. Pat. 2,756,- 135 and Belgian Pat. 687,019).

Furthermore, it is known that phenoxycarboxylic acids (2a) can be used as herbicides, particularly in cereals (see US. Pats. 2,740,810 and 2,322,760 and British Pat. 822,199). The following phenoxycarboxylic acids have attained substantial practical importance: 2,4-dichlorophenoxyacetic acid and 2-methyl-4-chloro-phenoxyacetic acid, as well as corresponding u-phenoXy-propionic acids.

Both such phenoxycarboxylic acids (2a) and such urea (la) are selective herbicides and thus have the disadvantage that, when used as selective herbicides, they do not adequately destroy or control all of the numerous types of weeds which occur in cereal oultivations. Understandably, those weeds which are uncontrolled then spread unusually rapidly, since they grow without further rivalry from the other weeds, and thus tend to negate the initial advantage of a given herbicidal treatment.

:It has been found, in accordance with the present invention, that new herbicidal compositions which comprise synergistic combinations of the active compounds.

(i) l-(benzothiazol-2'-yl)-1,3-dimethyl-urea having the formula:

and (ii) a phenoxycarboxylic acid compound having the formula:

Cl0-R-O 0 on in which *R is methylene or methylmethylene (i.e. ethylidene) and 'R is chloro or methyl,

said phenoxycarboxylic acid compound being in the form of a member selected from the group consisting of the corresponding alkali metal salt, lower alkyl amine salt and lower alkoxy-lower alkyl ester, in admixture in a ratio by weight of (i) to (ii) of substantially between 21:2 and 4:1, possess an especially broad and selective herbicidal activity in agricultural crops, especially among cereals.

Surprisingly, the herbicidal eliectiveness of the new synergistic combinations of active compounds according to the present invention is substantially higher than the sum of the separate effects of the individual active c0mpounds. This is not merely a supplementary or additive effect but rather a genuine synergistic ettect which was not to be foreseen. Significantly, this synergistic effect is particularly great when limited to specific ratios of concentration as noted above.

Advantageously, the synergistic combinations of active compounds according to the present invention are markedly superior to known active compounds such as the phenoxycarboxylic acids conventionally used for weed control in agricultural crops, for example, cereals. The instant synergistic combinations of active compounds thus constitute a valuable addition to the art of weed control agents, especially in cereal cultivation.

The ratio by weight of the active compounds in the instant synergistic combinations may be varied within a certain crtical range. In general, the given combination of active compounds contains substantially between about 33-80%, and preferably about 40-66%, by weight of l- (benzothiazol-2'-yl)-l,3-dimethyl-urea, with the remainder being such phenoxycarboxylic acid compound. The ratio by weight of 1(benzothiazol-2-yl)-l,3-dimethylurea to such phenoxycarboxylic acid compound thus lies, as aforesaid, between about 1:2 and about 4: 1, and preferably between about 1:15 and 2:1, i.e. 0.5-4zl, and preferably 0.67-221.

Advantageously, the instant synergistic combinations of active compounds have a very favorable herbicidal activity against weeds, without damaging the agricultural crops, especially cereals. They can, therefore, be used as markedly good selective herbicides.

The term Weeds as used herein is to be considered in the widest sense and thus is to be understood to mean all plants which usually occur as contamination of agri cultural crops, especially of cereal crops, or as otherwise undesired plants or vegation for the particular purposes in question.

As phenoxycarboxylic acid compounds according to Formula 2a, there may be mentioned the following, i.e. in terms of the free acids: 2,4-dichloro-phenoxyacetic acid, oz-(2,4 dichloro-phenoxy) propionic acid, 2-methyl-4- chloro-phenoxyacet-ic acid and u-(2-methyl-4-chloro-phenoxy)-propionic acid. Particular compounds which are preferred include the potassium, sodium and monomethylamine salt of a-(2,4-dichloro-phenoxy)-propionic acid; the sod-ium, potassium and monomethylamine salt of a-(Z- rnethyl-4-chloro-phenoxy)-propionic acid; the sodium, potassium and dimethylamine salt and the butylglycolester of 2,4-dichloro-phenoxyacetic acid; and the sodium, potassium and dimethylamine salt of 2-methyl-4-chloro-phenoxyacetic acid.

As is known, it is in principle the acid radical which acts herbicidally in the derivatives of the phenoxyoarboxylic acids. For this reason it is understandable that the different derivatives mentioned are usable instead of the pure acid. The statements of amount, such as amounts in the foregoing ratios and the amounts actually applied, always refer herein however to the free acids. The instant derivatives can advantageously be more simply formulated than the free acids.

The phenoxycar-boxylic acids as well as their derivatives mentioned have been long known as herbicides, and some of them have attained great practical importance (see German Pats. 915,876, 940,946 and 949,912 as well as German published patents (DAS) 1,064,286, 1,071,411 and 1,121,403).

In the synergistic combinations of'active compounds according to the invention, there may be used any of the previously known derivatives of the acids. Particularly suitable are salts of potassium, of sodium, of the three methyl amines, i.e. mono-, diand tri-methylamines, as well as esters of aliphatic alcohols, in particular of alkoxyalkyl alcohols, for example butylglycol alcohol. Some preferred compounds have already been mentioned above.

Thus, in Formula 2a above, R is methylene or methylmethylene R is chloro or methyl, and the compounds are the corresponding alkali metal salts such as the Na, K, Li, etc., salts; the corresponding lower al-kylamine salts such as the mono-, diand t1i-, same or diiferent, C alkylamine salts including the methyl, ethyl, nand iso-propyl, 11-, iso-, sec.- and/or tert.-butyl, and the like, mono-, diand tri-substituted amine salts; or corresponding lower alkoxy-lower alkyl esters such as the C alkoxy-C alkyl esters, including the methoxy, ethoxy, nand isopropoxy, n-, iso-, sec.- and tert.-butoxy, and the like, substituted methyl to tert.-butyl inclusive, and the like, as defined above, esters. Thus, the COOH radical may be designated COOZ to define the corresponding phenoxycarboxylic acid alkali metal or lower alkylamine salt or lower alkoxy-lower alkyl ester moiety.

Advantageousy, the synergistic combinations of active compounds according to the present invention show a very marked activity against weeds, without harming cereal species, in particular barley, wheat, rye and maize.

As weeds which are destroyed by the synergistic combinations according to the present invention and which often occur in cereals, there are mentioned for example: Dicotyledone'ae, such as knotgrass (Polygonum aaviculare), cornflower (Centaurea cyanus), cleavers (Galium aparine), corn poppy (Papaver rhoeas), fumitory (Fumaria ofiicinalis), common forget-me-not (Myasotis arvensis), deadnettle (Lamium spec.), Buxbaums speedwell (Veronica persica), corn spurrey (Spergula arvensis), doves foot cranesbill (Geranium molle), and Monocotyledoneae, such as silky bent-grass (Apera spica-venti) and annual bluegrass (Pow annua); and the like.

The particular synergistic combinations of active compounds according to the instant invention can be utilized, if desired, in the form of the usual formulations or compositions with conventional pesticidal diluents or extenders, i.e. conventional pesticidal dispersible carrier vehicles, such as solutions, emulsions, suspensions, emulsifiable concentrates, spray powders, pastes, soluble powders, dusting agents, granules, etc. These are prepared in known manner, for instance by extending the synergistic combination of active compounds with conventional pesticidal dispersible liquid diluent carriers and/or dispersible solid carriers optionally with the use of carrier vehicle assistants, e.g. conventional pesticidal surface-active agents, including emulsifying agents and/or dispersing agents, whereby, for example, in the case where Water is used as diluent, organic solvents may be added as auxiliary solvents. The following may be chiefly considered for use as conventional carrier vehicles for this purpose: dispersible liquid diluent carriers including inert organic solvents, such as aromatic hydrocarbons (e.g. benzene, toluene, xylene, etc.), halogenated, especially chlorinated, aromatic hydrocarbons (e.g. chlorobenzenes), paraflins (e.g. petroleum fractions), chlorinated aliphatic hydrocarbons (e.g. methylene chloride, etc.), alcohols (e.g. methanol, ethanol, propanol, butanol, etc.), ethers, ether-alcohols (e.g. glycol monomethyl ether, etc.), amines (e.g. ethanolamine, etc.), amides (e.g. dimethyl formamide, etc.), sulfoxides (e. g. dimethyl sulfoxide, etc.), ketones (e.g. acetone, etc.) and/or water; as well as dispersible finely divided solid carriers, such as ground natural minerals (e.g. kaolins, alumina, silica, chalk, i.e. calcium carbonate, talc, kieselguhr, etc.), and ground synthetic minerals (e.g. highly dispersed silicic acid, silicates, e.g. alkali silicates, etc.), whereas the following may be chiefly considered for use as conventional carrier vehicle assistants, e.g. surface-active agents, for this purpose: emulsifying agents, such as nonionic and/or anionic emulsifying agents (e.g. polyethylene oxide esters of fatty acids, polyethylene oxide ethers of fatty alcohols, alkyl sulfonates, aryl sulfonates, etc., .and especially alkyl aryl-polyglycol ethers, magnesium stearate, sodium oleate, etc); and/or dispersing agents, such as lignin, sulfite waste liquors methyl cellulose, etc.

As concerns commercially marketed preparations, these generally contemplate carrier composition overall mixtures in which the synergistic combination of active compounds is present in a total amount substantially between about 01-95%, and preferably 05-90%, by weight of the overall carrier composition extended mixture, whereas overall carrier composition mixtures suitable for direct application or field application generally contemplate those in which the synergistic combination of active compounds is present, e.g. in the form of a dosage unit preparation containing substantially between about 0.5-4, and preferably 1-3, kilograms of the synergistic combination per hectare of soil being treated. Thus, the present invention contemplates selective herbicidal compositions which comprise overall carrier composition extended mixtures of a conventional dispersible carrier vehicle such as (1) a dispersible carrier solid, and/or (2) a dispersible carrier liquid such as an inert organic solvent and/or water preferably including a surface-active effective amount of a carrier vehicle assistant, e.g. a surface-active agent, such as an emulsifying agent and/or a dispersing agent, and an amount of the synergistic combination of active compounds, e.g. in a ratio of 0.5-4:1 therebetween, which is effective for the purpose in question and which is generally between about 01-95% by weight of the overall carrier composition extended mixture. Specifically, the synergistic combination of the active compounds may be applied in the form of a herbicidal composition to a sur face area, for example, to agricultural soil for selective weed control in agricultural crops, such as in post-emergence use, in concentrations such that said synergistic combination is distributed in a dosage of substantially between about 0.5-4 kg. per hectare of soil being treated, preferably 1-3 kg. per hectare, although it will be appreciated that in connection with the pre-emergence use of the instant compounds, as well as the post-emergence use thereof, the concentration may be varied within a fairly wide range, depending on various factors such as the composicompatible with the cultivated plant. In these cases, therefore, the selectivity, and thus the herbicidal index, is clearly increased. In the case of combinations of active compounds without synergistic effect, a mere broadening of tion of the synergistic combination, the conditions of culthe spectrum of activity is expected, but not an increase tivation, soil, weeds, e.g. in cereal cultivation, weather, of the selectivity. Generally, without synergism, the sum and the like. However, generally the pro-emergence range of the effects to be expected from a given combination of of concentration of the synergistic combination will be active compounds understandably depends on the mixing 01-95% by weight of the overall mixture as aforesaid, ratio and lies between the individual effect of the less efwhile the post-emergence range of such synergistic comfcctive and that of the more effective active compound. bination will be between about 0.5-4 kg. per hectare, as From the tables of the examples it can be clearly seen aforesaid, i.e. with or without the carrier vehicle. that the combinations of active compounds according to Furthermore, the present invention contemplates meththe invention show a genuine synergistic effect. The herods of selectively controlling or combating undesired bicidal effect of the combinations of active compounds is plants, e.g. weeds and the like, especially in cereal cultivaalways higher than the herbicidal activity of the more eftion, which comprise applying to at least one of (a) such fective individual active compound. weeds and (b) their habitat, i.e. the locus to be protected,

EXAMPLE 1 a herbicidally effective amount of a herbicidal composition containing the particular synergistic combination of Post-Emergence test/OutdoorsPray Powder active compounds 9 the invehtioh 819116 together in an Inert carrier material: 0.25 part by weight kaolin and overall mixture with a carrier vehicle as noted above. silicic acid (3:1) The mstant formulatlons composltlonsfire @2 5! Protective colloid: 0.02 part by weight lignin sulfate the usllal mamferi for exflmplei ,SPraYmg, f Dispersion auxiliary: 0.15 part by weight hydroxyarylsulscattering, dusting, watering, sprinkling, vaporiz ng, and fonic acid formaldehyde condensate. the hke, whether for post-emergence apphcation' to the weeds, which is the preferred procedure, or pre-emergence To produce a suitable active compound preparation, 1 application to the soil, and generally in amounts such that, part by Weight of the active compound combination was regardless of the presence or absence of the carrier veixed wi h t e stated amounts of the foregoing formulahicle, and/or other compatible active agents, substantially n Xiliari and the resulting Concentrate Was then between about 0.5-4 kg. of the synergistic combination diluted with water to the desired final concentration. are distributed per hectare of soil being treated, Plots outdoors with test plants which had a height of The favorable herbicidal effect of the instant combinaabo t 3-10 cm. were sprayed with such an amount of the tions of active compounds can be seen from the following active Compound Prfipafatlon that a uniform Wetting exam le Whereas the individ al a tive compounds exthe plants occurred. The amount of active compound aphibit deficiencies with regard to their herbicidal effect, the p i d P r unit area is decisive. After three Weeks the instant synergistic combinations have every broad activdegree of damage of the plants was determined and charity against weeds, which exceeds the mere sum of the inamt-filed y the Vahlfis Whlch have the following dividual effects. meamng:

In the case of selective herbicides, a synergistic effect is 0 efi t always considered to be present when, with the same 40 ml b t t amounts applied, the herbicidal effect of the given coma g y i s bination of active compounds on the weeds is equal to i i 0 s t 1k H d d or greater than the herbicidal effect of the more effective 3 f i i S a 5 par la y ea individual active compound alone, while at the same time par g a the herbicidal effectiveness of the combination of active p an Comp 6 e y ea compounds on the cultivated plant itself is equal to or The active compounds or synergistic combinations testless than the herbicidal effectiveness on such cultivated ed, the amounts used and the results obtained can be seen plant of that individual active compound which is most from the following Tables la and lb.

TABLE 1a Post-emergence test (outdoors) Amount Polyapplied Apera Cent- Fumaria qonum Gerain kg./ Poa spicaaurea ojficavi- Lamium m'um Active compound hectare Wheat Maize unnua venti cyimua malts culare spec. mall:

(1a) is a 0 o-1 5 5 3 4 5 5 5 CH; 0 2.5 0 0 4 4-5 2 a 4 4 4 i ll 2 0 0 3-4 3-4 1-2 2-3 3-4 3-4 3-4 C--N-O-NH-CH: N

(known).

(294)-- 3 2-3 0 0 5 5 4-5 a 3 CI O-CIh-COOH 2.5 o 2 0 o 4-5 4 4 2 2-3 2 1 0 0 4 3-4 3-4 1 2 as sodium salt (known).-

241)-- 3 0 2 0 0 5 5 3-4 2 3 ClOOHrC 0 0H 2. 5 o 1-2 0 0 4-5 4 a 1-2 2 2 0 1 o 0 3-4 3-4 2 1 2 (3H1 as sodium salt (known). Mixture of (1a) and (2m) (sodium salt) 3 0 0-1 5 5 5 5 5 5 5 (according to invention) 2. 5 0 0 4 4-5 4-5 4-5 4-5 4-5 4 Weight ratio2z1. 2 0 o 3-4 3-4 4 4 4 4 3-4 Mixture of (1a) and (2a,) (sodium salt) 3 0 0-1 5 5 5 5 5 5 5 (according to invention) 2. 5 0 0 4 4-5 4-5 4 4 4 4-5 Weight ratio 2:1. 2 0 0 3-4 3-4 4 4 3-4 3-4 4 TABLE 1b Post-emergence test (outdoors) Amount applied Apera in kg./ spica- Galium Papaver Myosotis Veronica Spergula Active compound hectare Barley Rye venti apan'ne rhoeas arvemis persican'a arvensie (1a) S 3 0-1 1 5 3-4 5 5 4-5 5 CH; 0 2. 5 0 0 4-5 3 4 3-4 4 4 I ll 2 0 0 3-4 2-3 3 3 3-4 3 GN-CNHCH;

(known).

(2a CH; 3 1-2 0 4 5 3 3 4 2. 5 0 0 0 3-4 4 2-3 2-3 3-4 01-- O-CH-CO 0H 2 0 0 3 3-4 2-3 2 3 as potassium salt (known).-

(2a CH: 3 1-2 0 4-5 5 3 3 3 2. 5 0 0-1 0 4 4 2-3 2 2-3 Cl 0-CHCO OH 2 0 0 3-4 3-4 2 1-2 2-3 as potassium salt (known): Mixture of (la) and (2a;) (potassium salt) 3 0 0 5 4 5 5 5 5 (according to invention) 2. 5 0 0 4-5 4 4 4 4 4-5 Weight ratio 2:1. 2 0 0 3-4 3-4 3-4 3 4 3-4 Mixture of (1a) and (2m) (potassium salt) 3 0 0 5 4-5 5 5 5 5 (according to invention) 2. 5 0 0 4-5 4 4 4 4 4 Weight ratio 2:1. 2 0 0 3-4 4 3-4 3 4 3-4 EXAMPLE 2.

This example was carried out in a manner similar to that used and the results obtained can be seen from the folof Example 1. The active compounds tested, the amounts lowing Tables 2a and 2b:

TABLE 2a Post-emergence test Concentration 0! active compound Galinaoga Urtica Stellaria Active compound in percent parviflora urena media Wheat Barley /ONCNHOHa (kno'wn);

2a)..-- 0.1 2.0 4.1 0.6 0 0 ci--o-omcoon i 01 as sodium salt (known).-

Cl- OCHr-C 0 OH as butylglycol ester (known). Mixture of (la) plus (29.1) (sodium salt) (according to invention) Weight ratio:

4:1-.- 0.1 5 5 5 0 0 0.1 4.8 5 4. 8 0 0 0. 1 4. 8 5 4. 6 0 0 0. 1 4 4. 5 4 0 0 (la) plus (2215) (ester) (according to invention) Weight ratio:

4:1 0. 1 5 5 5 0 0 0.1 5 5 4. 8 0 (J 0. 1 4.8 4.3 4. 7 0 0 0. 1 4. 6 4. 2 4. 5 U U TABLE 2b Postemergence test Concentration of active compound Urtica Stellaria Galimoqa Gulium Active compound in percent Wheat Rye umm media parmflora uparim r r CNCNHCH (known).

(2a.) CE: 0.1 o 0. 4 2. 5 4. 0 2.8 a. s

c1-Qo-dn-ooorr as sodium salt (known).-

(22 1H; 0. 1 o 0. 2 2. a 4. 0 3. 5 3. 8

o1--0-orr-ooon as monomethylamine salt (known).

Mixture of (la) plus (2a.) (sodium salt) (according tolnvention) Weight ratio:

4=1 0.1 o 0.4 5 5 5 3.8 2=1. 0.1 0 0.3 5 5 4.5 4.0 1:1.5 0.1 o 0.3 4.5 4.8 4.0 4.0 1:2 0.1 o 0.3 4.0 4.3 3.5 4.2 Mixture of (la) plus (2& (monomethylamlne salt) (according to invention) Weight ratio:

4:1 0 1 0 0 2 5 5 4.5 3.8 0 1 o 0 2 5 5 4.2 4.0 1: 01 0 01 4.8 4.8 4.0 4.2 1:2 0 1 o o 2 4.0 4.5 3.5 4.2

It will be realized by the artisan that all of the fore- (ii) a phenoxycarboxylic acid compound having the going synergistic compositions of active compound comformula binations contemplated by the present invention possess the desired selective herbicidal properties, as well as a l-OROOOH comparatively low toxicity toward warm-blooded crea- R tures and a concomitantly low higher plant phytotoxicity, enabling such synergistic combinations of active compounds to be used with correspondingly favorable compatibility with warm-blooded creatures and higher plants for more elfective control and/or elimination of weeds, especially in cereal cultivation, by application of such synergistic combinations of active compounds to such weeds and/or their habitat. Nevertheless, the instant synsalt and lower alkoxHower alk l ester in admixture ergistic combinations possess total herbicidal action when in a ratio by Wei ht of (i) toyw) substantially used in large quantities, although selective herbicidal ac- 5 between about 0 5 tion is obtained when used in smaller quantities. As con- 2 Composition acordi'n to claim 1 wherein said ratio templated herein, the term weeds" is meant to include by ;veight is between aboit 0 not only weeds in the narrow sense, but also in the broad 3 composition according i 1 wherein said i g g all i g and vegetation synergistic combination is in the form of a carrier comere un eslra e or e artrc at ur ses 1n uestlon.

It will be appreciated that the insfanfzpecifica iion and poS-ltlon -mlxtum a dispel-AS1131? Gamer Y which said synergistic combination is present in a herbiexamples are set forth by way of illustration and not lrmcidany effective amount itation, and that various modifications and changes may 4 Composition accrding to claim 1 wherein said be made wxihout flepamflg fi'om the and scope of synergistic combination is in the form of a carrier comthe present mvemlon which Is to be hunted only by the position mixture with a dispersible carrier vehcle, in

scope of the appended clams which said synergistic combination is present in a herbi- What is claimed is:

1 Synergistic herbicidal composition which consists cidally effective amount and constitutes substantially between about 0.1-95% by weight of the'carrier composiessentially of an effective amount of a synergistic COmbltion mixture in which R is selected from the group consisting of methylene and methylmethylene and R is selected from the group consisting of chloro and methyl, said phenoxycarboxylic acid compound being in the form of a member selected from the group consisting of the corresponding alkali metal salt, lower alkylamine nation of 5 C omposrtion according to claim 1 wherein said ggig 2 methyl-urea havmg the synergistic combination is in the form of a carrier composition mixture with a dispersible carrier vehicle selected from the group consisting of (1) a dispersible finely s CH 0 divided carrier solid and (2) a dispersible carrier liquid a 7 selected from the group consisting of an organic solvent,

NH-CH| water and mixtures thereof containing a surface-active agent selected from the group consisting of anionic emulsifying agents, non-ionic emulsifying agents, dispersing agents, and mixtures of such agents, in which said synerand gistic combination is present in a herbicidally elfective 1 1 amount and constitutes substantially between about 0.1- 95% by weight of the carrier composition mixture.

6. Method of using a composition according to claim 1 for combating weeds which comprises applying to at least one of (a) such weeds and (b) their habitat, a herbicidally eifective amount of such herbicidal composition contaim'ng a synergistic combination according to claim 1.

7. Method according to claim 6 wherein said ratio by weight is between about 0.67-2: 1.

8. Method according to claim 6 wherein said synergistic combination is used in the form of a carrier composition mixture with a dispersible carrier vehicle, in which said synergistic combination is present in a herbicidally elfective amount.

9. Method according to claim 6 wherein said synergistic combination is used in the form of a carrier composition mixture with a dispersible carrier vehicle, in which said synergistic combination is present in a herbicidally etfective amount and constitutes substantially between about 0.1-95% by weight of the carrier composition mixture.

10. Method according to claim 6 wherein said synergistic combination is used in the form of a carrier composition mixture with a dispersible carrier vehicle selected from the group consisting of (1) a dispersible finely divided carrier solid and (2) a disposable carrier liquid selected from the group consisting of an organic solvent, water and mixtures thereof containing a surface-active agent selected from the group consisting of anionic emulsifying agents, non-ionic emulsifying agents, dispersing agents, and mixtures of such agents, in which said synergistic combination is present in a herbicidally effective amount and constitutes substantially between about 0.1- 95% by weight of the carrier composition mixture.

11. Method according to claim 6 wherein said herbicidal composition is applied to agricultural soil for selective weed control in agricultural crops, in an amount such that said synergistic combination is distributed in a dosage of substantially between about 0.5-4 kg./hectare of soil being treated.

12. Method of using a composition according to claim 1 for combating weeds in cereals which comprises apply- 12 ing to at least one of (a) such weeds and (b) their cereal habitat, a herbicidally efiective amount of a herbicidal composition containing a synergistic combination of (i) 1-(benzothiazol-2'-yl)-1,3-dimethyl-urea having the formula and (ii) a phenoxycarboxylic acid compound having the formula ergo-1pc 0 011 References Cited UNITED STATES PATENTS 3,151,970 10/1964 Lush et a1. 71116 2,756,135 7/1956 Searle 7l90 2,709,648 5/1955 Rykcr et a1. 7l117 2,396,513 3/1946 Jones 71-l17 LEWIS GOTTS, Primary Examiner C. L. MILLS, Assistant Examiner US. Cl. X.R.

v UNITED ST/ FES PATENT OFFICE I CERTIFICATE 9F CQRRECTEQN Patent No. 3 682, 614 Dated Augu t 8 1972 Invent0r(s) Helmuth Hack et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1

Patent should be identified as being Assigned to 1 "FARBENFABRIKEN BAYER AKTI'ENCESELLSCHAFT, Leverkusen;

Germany", I

Col. 2 line 45 "crtical" should be critical "vegation" should be vegetation Col. 3 line 42 efter "methylene" insert Col. 3 line 57 "Advantageousy" should be Adv'an tageotisly Col. 3 line 65 "cleavers" should be cleaver UNHEU .CS'IA'IK'IS PA'IIIN'F ()FHCE CE Rfivllilq (I ATE O l C0 R H. ECT Q N Dated August 8, 1972 Patent No.

Invent0r(s) HGlmuth Hack et: a1

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

Col. 6 line 37 "0.5 should be 0-5 -e.

Col. 9, Active compound la in Table s cu o I 3 I (EH3 9| C--N--C-NH---Cfl should be C-- N-- CNH--CH Col. 10, line 60 '"vehcle" should be vehicle Signed and sealed this Zlgth day of April 1973.

(SEAL) Attest: I

' 'ROBERTGOTTSCHALK EDWARD M.FLE;TCHER,JR. Attesting Officer Commissioner of Patent UNI'IED sm'ms PATENT mrmcs CERTIFICATE OF CURRECTIUN 1 mm NO. 3,682,614 7 D August a. 1972 Inventor(s) Helmuth Hack et al' It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1

Patent should be identified as being Assigned to I "FARBENFABRIKEN BAYER AKTIENGESELLSCHAFT, Leverkusen,

Germany".

Col. 2 line 45 "crtical" should be critical "vegatio'n" should be vegetation Col. 3 line 42 after "methylene" insert Col. 3 line 57 "Advantageousy" should be Advantageotisly Col. 3, line 6'5 "cleavers" should be cleaver 0mm) s'm'mcs iA'll-JN'I 0mm;

CEFJR'H:.WI(l ATE 0 l3 (10B R. ECTFQGN Patent No. 3 ,682,6l Dated August 8, 1972 Inventor(s) Helmuth Hack et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

Col. 6 line 37 "0.5" should be 0-5 Col. 9, Active compound la in Table II N C N C NH CH should be C N C CH Col. 10 line 60 "'vehcle" should be vehicle Signed and sealed this 2Lpthday 'of April 1973.

(SEAL) Attest:

EDWARD TCHER ,JR. I ROBERT GOI'TSCHALK Commissioner of Patents Attesting Officer UNI'IED smfms PATENT mwmr: CERTIFICATE Q}? CURRECTIUN Patent No. 3,682,614 7 Dated August 1972 Inventor(s) Helmuth Hack et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1 Patent should be identified as being Assigned to "FARBENFABRIKEN BAYER AKTIENGESELLSCHAFT, Leverkusen;

Germany".

Col. .2 line 45 "crtical" should be critical C01. 3 li"e 2 "vegation" should be vegetation Col. 3 line 42 efter' "methylene" insert Col. 3 line 57 "Advantageousy" should be Adv'an tageously Col. 3 line 65 "cleavers" should be cleaver UNi'll'll .S'IA'H'IS IA'II'IN'F OFFICE C E RT H. I (I A T E 0 If? C 0 H Ei. E (31 E; 0 N

Patent No. 3 682 ,614 Dated August 8, 1972 Inventor(s) Helmuth Hack et a1 It is certified that error appears in the abovc-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 6 line 37 "0.5" should be 0-5 Col. 9, Active compound la in Table s on 0 I 3 I 3 9 9| n II %C N C NH CH should be C N C CH Col. 10 line 60 -"vehcle" should be vehicle Signed and sealed this Zlgthday of April 1973. V

(SEAL) Attest:

EDWARD M.FLE;TCHER,JR. ROBERT GOTTSCHALK Commissioner of Patents Attesting Officer Col. 3 line 65 UNHED STATES PATENT (,H FKIE CERTIFICATE 0F CQRRECTIUN Patent No. 3,682,614 Dated AugllSt 8. 197

Inventor(s) Helmuth Hack 8t 81 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1

Patent should be identified as being Assigned to "FARBENFABRIKEN BAYER AKTIENGESELLSCHAFT, Leverkusen,

Germany". I

Col. 2 line 45 "crtical" should be critical Col. 3 1i": 2

"vegation" should be vegetation Col. 3 line 42 after "methylene" insert Col. 3 line 57 "Advantageousy" should be Advantageously "cleavers" should be cleaver UM'H-cn s'r/vrus m'rrcwr (1mm;

(.1 ER'FII I (ll A1 I) O (10H EC. L9 CT 0 N Patent No. 3 682 614 Dated August 8, 1972 Invent0r(s) Helmuth Hack et al I 2 It: is certified that error appears in the nbove-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 6 line 37 "0.5" should be 0-5 Col. 9, Active compound la in Table S\ 111 I 2H 9 cN-c-NH-cn h ldb N 3 5 cu e C N. C NH CH Col. 10 line 60 "vehcle" should be vehicle Signed and sealed this Zhth day of April 1973.

(SEAL) Attest:

EDWARD M.FLETCHEH ,JR. ROBERT GOTTSCHALK Attesting Officer 7 Commissioner of Patents 

